Guatemala's Supreme Court has refused a request by prosecutors to lift the immunity of Edgar Justino Ovalle, a lawmaker and adviser to President Jimmy Morales.

Ovalle is a former military officer accused of participation in rights abuses during the 1960-1996 civil war. He is now a member of Congress, which gives him immunity from prosecution.

Court spokesman Angel Pineda said Thursday the justices didn't find "reasonable evidence that could prove the congressman's involvement in the events."

The president is a former TV comic and political neophyte whose candidacy was linked to former military officers.

More than a dozen retired military figures have been arrested in the same case. Many belong to a veterans group that supports the National Convergence Front, the party Morales ran for. Ovalle is a party founder.